Alert archive / Colorado / Tornado Warnings in 2021

Tornado Warning 22, NWS Denver/Boulder, CO

May 23, 2021Logan County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at May 23, 2021, 4:10 PM MDT for Logan County, Colorado. It was in force for 20 min. 6 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 23, 2021, 4:10 PM MDT (22:10 UTC)
Expired
May 23, 2021, 4:30 PM MDT
In force
20 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Observed
Damage threat
Considerable
Hail
1.5 in

County Logan County, CO

The radar

The Cheyenne radar (KCYS), 159 km from the middle of the area, began a volume at 22:10 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
May 23, 4:11 PM MDTHAIL 0.75Iliff, COREPORT FROM MPING: DIME (0.75 IN.).
May 23, 4:11 PM MDTHAIL 1Iliff, COREPORT FROM MPING: QUARTER (1.00 IN.).
May 23, 4:30 PM MDTHAIL 1.5Iliff, CO
May 23, 4:30 PM MDTTORNADO1 W Proctor, COEMERGENCY MANAGER REPORTED POWER POLES DOWN NEAR PROCTOR. LIKELY TORNADO DAMAGE. TIME ESTIMATED.
May 23, 4:35 PM MDTHAIL 35 Nnw Proctor, COREPORTED VIA FACEBOOK.
May 23, 4:40 PM MDTTSTM WND GST 612 E Sterling, COMESONET STATION I-76.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 23, 12:06 PM MDTTornado WatchSPC8 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 10.2 hours before the alert went out and 95 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2021-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2021-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1106 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

038 
WFUS55 KBOU 232210
TORBOU
COC075-232230-
/O.NEW.KBOU.TO.W.0022.210523T2210Z-210523T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
410 PM MDT Sun May 23 2021

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  Central Logan County in northeastern Colorado...

* Until 430 PM MDT.

* At 409 PM MDT, a confirmed large and extremely dangerous tornado
  was located 6 miles northeast of Sterling, moving northeast at 40
  mph.

  This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW!

  HAZARD...Damaging tornado.

  SOURCE...Weather spotters confirmed tornado.

  IMPACT...You are in a life-threatening situation. Flying debris 
           may be deadly to those caught without shelter. Mobile 
           homes will be destroyed. Considerable damage to homes, 
           businesses, and vehicles is likely and complete 
           destruction is possible.

* Locations impacted include...
  Sterling, Iliff, Crook and Proctor. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a large, extremely dangerous and potentially deadly
tornado is on the ground. To protect your life, TAKE COVER NOW! Move
to a basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 4056 10300 4062 10320 4094 10309 4087 10277
TIME...MOT...LOC 2209Z 203DEG 35KT 4066 10308 

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CONSIDERABLE
HAIL...1.50IN

$$

DANIELSON

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 6:06 PM MDTTornado WarningBOUWashington24 min
May 22, 8:00 PM MDTSpecial Weather StatementBOUPhillips30 min
May 22, 8:29 PM MDTSpecial Weather StatementBOUPhillips, Sedgwick46 min
May 22, 9:37 PM MDTSevere Thunderstorm WarningBOULincoln38 min
May 23, 12:40 PM MDTTornado WarningBOUElbert, Lincoln19 min
May 23, 12:41 PM MDTSpecial Weather StatementBOUWeld49 min
May 23, 12:50 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln40 min
May 23, 1:24 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln36 min
May 23, 1:28 PM MDTSpecial Weather StatementBOUWeld32 min
May 23, 1:47 PM MDTTornado WarningBOUArapahoe, Elbert, Lincoln, Washington28 min
May 23, 2:13 PM MDTTornado WarningBOUWashington32 min
May 23, 2:44 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington31 min
May 23, 2:55 PM MDTTornado WarningBOUWashington20 min
May 23, 3:11 PM MDTTornado WarningBOULogan, Washington34 min
May 23, 3:14 PM MDTSevere Thunderstorm WarningBOUArapahoe, Elbert, Lincoln, Washington46 min
May 23, 3:42 PM MDTTornado WarningBOULogan33 min
May 23, 4:06 PM MDTAreal Flood AdvisoryBOUWashington3 hr
May 23, 4:27 PM MDTTornado WarningBOULogan23 min
May 23, 4:43 PM MDTTornado WarningBOUWashington17 min
May 23, 4:58 PM MDTTornado WarningBOUWashington17 min
May 23, 5:12 PM MDTAreal Flood AdvisoryBOULogan, Washington104 min
May 23, 5:13 PM MDTSevere Thunderstorm WarningBOULogan, Phillips, Washington32 min
May 23, 5:31 PM MDTTornado WarningBOUWashington14 min

Nearby

Tornado Warnings in Colorado, 2021Every tornado warning in 2021Tornadoes in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.